(PS2-94) Examining the Drift: An Investigation on Working and Episodic Memory Performance in Anhedonia

Depression is commonly associated with cognitive deficits, including memory difficulties. Evidence suggests there is a preferential recall of negative over positive information and difficulties removing irrelevant information from working memory, which newer research suggests association with underlying reward-processing impairments. This study aimed to examine whether individuals with low hedonic capacity had more difficulty removing negative stimuli from their working memory and more efficient evidence accumulation of these images the next day and vice versa for positive stimuli, compared to controls who scored in the normal hedonic range. Young adults (n=105) with a range of anhedonia symptoms completed a working memory task where they had to remember one or two abstract shapes while presented with positive, neutral, and negative distractors. The task was followed by a surprise recognition test of the distractors the next day. We used the Diffusion Drift Model (DDM; Ratcliff & McKoon, 2008) to examine differences in the evidence accumulation rate (i.e., drift rate) across groups using multivariate multiple regressions. Contrary to our hypotheses, Dimensional Anhedonia Rating Scale (DARS) scores did not statistically significantly predict the average drift rates of negative, positive, or neutral trials, when controlling for age, gender, and psychiatric medication use. That is, anhedonia severity was not associated with the rate of accumulation for neutral stimuli (i.e., abstract shapes) when the distractors were emotionally valenced. Similarly to the working memory task, the linear regression results indicated that DARS scores did not statistically significantly predict the “old” positive drift rate, or rate of accumulation of positive trials, when controlling for age, gender, and psychiatric medication use. Our findings suggest that young adults with anhedonia perform similarly to same-aged healthy controls in that negative distractors impair working memory for abstract stimuli, compared to positive and neutral distractors. Similarly, evidence accumulation rates for positive stimuli in a recognition task were similar across levels of anhedonia.